Results 11 to 20 of about 3,200 (163)

Complex and nonlinear climate‐driven changes in freshwater insect communities over 42 years

open access: yesConservation Biology, Volume 34, Issue 5, Page 1241-1251, October 2020., 2020
Abstract The ongoing biodiversity crisis becomes evident in the widely observed decline in abundance and diversity of species, profound changes in community structure, and shifts in species’ phenology. Insects are among the most affected groups, with documented decreases in abundance up to 76% in the last 25–30 years in some terrestrial ecosystems ...
Viktor Baranov   +4 more
wiley   +1 more source

A spatially explicit empirical model of structural development processes in natural forests based on climate and topography

open access: yesConservation Biology, Volume 34, Issue 1, Page 194-206, February 2020., 2020
Abstract Stand structure develops with stand age. Old‐growth forests with well‐developed stand structure support many species. However, development rates of stand structure likely vary with climate and topography. We modeled structural development of 4 key stand variables and a composite old‐growth index as functions of climatic and topographic ...
Yuichi Yamaura   +6 more
wiley   +1 more source

Superior Abrasibility of YSZ(ESP)/BN@ZrO2‐Polyester Composite Sealing Coating Reinforcing With Hybrid Micron/Nanometer Multiscaled Pore Structure

open access: yesRare Metals, Volume 45, Issue 5, May 2026.
ABSTRACT Composite materials hold significant potential for abrasive sealing, yet composite materials used for abrasive sealing fall short in service durability under extreme environments. Here, a controllable strategy for adjusting pore structure is proposed, aiming to design a YSZ(ESP)/BN@ZrO2‐polyester coating with hybrid micron/nanometer ...
Shuang Yu   +8 more
wiley   +1 more source

Devices of Graphene Synthesized by Laser Chemical Vapor Deposition and Research on the Key Technologies [PDF]

open access: yes, 2015
基于石墨烯优异的电子、机械、热学、光学性能以及广阔的应用前景,自2004年被发现以来迅速成为材料学与物理学领域的研究热门。目前,制备石墨烯的方法有很多,但是如何实现石墨烯的快速生长、生长区域的可控性、微区生长以及非转移生长一直是石墨烯在电子器件上应用必须解决的问题。通过对石墨烯多种制备方法的比较,我们发现激光化学气相沉积法(LaserChemicalVaporDeposition,LCVD)是最有可能实现这一要求的方法,本文也将采用该方法进行石墨烯的制备 ...
陈永庆
core  

Research on the Non-uniform Temperature Field for Purifying Polysilicon in Large Directional Solidification Equipment [PDF]

open access: yes, 2015
太阳能资源分布广泛并可无偿获取,使光伏发电成为新型能源的重要发展方向之一。因其发电组件具备建设周期短、安全可靠、布置灵活等优点得到了人们的青睐。硅作为光伏发电主要的基础材料,已占据市场90%以上的份额。冶金法提纯多晶硅具备投产建设速度快、提纯工艺流程短、成本较化学法低等优点,近年来发展迅速,受到国内外的广泛重视。 定向凝固是冶金法的核心。与中小型提纯相比,大型定向凝固的生产效率高,综合成本较低,但固液界面较难维持水平,晶粒不易保持垂直方向上的整齐排列,凝固和退火过程中裂锭的概率也较大,对温度场构建 ...
朱徐立
core  

Success of restoration strategies in preventing extirpation of 2 critically endangered coral species

open access: yesConservation Biology, Volume 40, Issue 2, April 2026.
Abstract An unprecedented marine heatwave in 2023 caused widespread coral bleaching and mortality throughout the Caribbean. In the Florida Keys (USA), 2 foundation species, elkhorn coral (Acropora palmata) and staghorn coral (Acropora cervicornis), were severely affected.
Erinn M. Muller   +29 more
wiley   +1 more source

Focus facula measurement in graphene preparation by laser chemical vapor deposition [PDF]

open access: yes, 2017
激光化学气相沉积(Laser Chemical Vapor; Deposition,LCVD)石墨烯制备受聚焦光斑影响很大。实时检测光斑,可实现石墨烯LCVD; 法可控制备。设计聚焦光斑测量光学系统,提出一种基于圆拟合的改进算法检测光斑中心和半径,计算、标定光斑面积。该方法在圆拟合基础上加入了二值化、形态; 学处理及连通性判别等预处理方法。实验表明,该方法测得圆心位置与真值误差平均为5. 58 pixel,光斑面积与真值误差平均为1.
刘婷婷, 张建寰, 李珊文, 林坤
core   +1 more source

High‐Brightness Delayed Imaging Realized by Embedding Zinc Gallate Nanocrystals Into Glass

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT X‐ray delayed imaging technology leverages an “irradiation‐storage‐thermally stimulated readout” mode, demonstrating unique advantages in intermittent monitoring scenarios such as high‐temperature/high‐radiation environments. This typically requires materials combining abundant carrier‐trapping energy levels with structural thermostability ...
Jun‐Xiao Wu   +6 more
wiley   +1 more source

电热耦合场分析在±800 kV穿墙套管电场分布计算应用

open access: yesGaoya dianqi, 2023
800 kV穿墙套管在特高压直流输电工程中发挥着重要的作用,但在应用有限元分析方法对其进行电场仿真优化设计时,往往忽略穿墙套管实际运行时的温度对电场分布的影响。文中首先建立了±800 k V穿墙套管三维仿真模型,通过仿真计算得到穿墙套管的温度场分布,考虑了实际运行中,套管发热对内部环氧芯体电导率的影响,并在温度场分布的基础上,应用电热耦合场分析计算的方法,获得穿墙套管的电场分布。计算结果表明:正常运行时,穿墙套管载流导杆及卷制管温度呈现中间高两边低的分布规律,靠近导杆的芯体温度高,沿径向方向 ...
韩晓东   +5 more
doaj  

等离子体反应器流场、温度场和浓度场的参数研究 [PDF]

open access: yes, 1987
文献[3,4]表述了描述等离子CVD化学反应器流场的数学物理模型,并利用Patankar方法对冷热流场作了求解。本文在此基础上就影响反应器流场、温度场和浓度场的有关参数作了理论研究。所研究的问题有:冷热流场的差别,喷射环缝密度和主流旋转速度对流动的影响。所得结果清楚地表明:这些参数的选择对反应器的性能有着不同程度的影响 ...
朱清文, 赵国英
core  

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